Typewriting machine



Nov. 1, 1938. w. F. HELMOND TYPEWRITING MACHINE 2 Sheets-Sheet 1 FiledAug. 15, 1935 //7 venfor;

Nov. 1, 1938 w. F. HELMOND TYPEWRITING MACHINE 2 Sheets-Sheet 2 FiledAug. 15, 1935 spaced from the rocker-arm axis.

Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE TYPEWRITING MACHINEApplication August 15, 1935, "Serial 'No. 36,272

14 Claims.

This invention relates to the paper-feed or pressure rolls that areassociated with the platenroll of a typewriter.

A feature of the invention is the provision, in

combination with spring-means for the bottom feed-rolls, of noveldevices designed to facilitate adjustment of said spring-means toregulate the bottom feed-roll pressure, and to gain other advantages.

lU A further feature of the invention resides in an improvedbooster-spring device usable at will, as when typing a stiff work-sheet,for applying to the bottom feed-rolls, spring-pressure which isadditional to or above the regular spring-pressure.

Two sets of main feed-rolls, front and rear, at the bottom of the platenare carried by means of rocker-arms. The rocker-arms, for each bottomfeed-roll set, are connected by a cross-rod A drawspring, for pressingthe bottom feed-rolls against the platen, is connected across thecross-rods and is therefore common to both sets of bottom feed-rolls.One of the rocker-arm-connecting 25 rods is notched by means of ascrew-thread pro-, vided thereon. One end of the draw-spring is anchoredin and is differentially locatable by means of said screw-thread notchesfor adjusting the spring-pressure, and the other end of the 30draw-spring may be fixed to the other cross-rod.

The draw-spring will be at least tension when it extends squarely acrossthe rocker-arm-connecting cross-rods. By slanting the spring across thecross-rods its tension will be increased. This 35 slanting of thespring, for adjustment of the feed-roll pressure, may be efiecteddifierentially by shifting the screw-thread-engaging end of the springto different notches as by merelyd-rawing the spring-end out of onenotch of the screw- 40 thread and passing it to another notch. Theadjustment may also be efl'ected by turning the threaded cross-rod, thethread then acting to move the draw-spring end along the cross-rod, likea nut held against rotation, to slant the 45 spring more or less,depending upon the direction and extent of turning the threadedcross-rod. Additional locking devices are not necessary to maintain thedraw-spring in its adjusted-position since the adjustable draw-springend cannot of 50 itself creep along the thread of the cross-rod, nor canthe threaded cross-rod turn of itself since it is frictionally held bythe tension of thedrawspring.

For applying more than the regular spring- 55 pressure upon thefeed-rolls, as when a stiff arm-connecting cross-rods to press upon thelatter. A spring-flexing finger may be brought into play manually bymeans of a handle to bear upon said leaf-spring at a point between saidcross-rods and flex said spring, and thereby cause it to put additionalspring-pressure upon both sets of bottom feed-rolls by way of saidcrossrods.

Withdrawal of said finger by means of said handle will remove the extraspring-pressure from the bottom feed-rolls. Said finger may be maderesiliently yieldable, as by mounting it upon a resiliently yieldablesupport, for the purpose that when the bottom feed-rolls are cast off,said finger, if it be effectively positioned, may yield and therebyobviate excessive flexing of the already flexed booster-spring.

The booster-spring may press upon the rockerarm-connecting cross-rodsintermediately of the ends of the latter, so that it may act uniformlyupon the bottom feed-rolls. In order that the primary or adjustabledraw-spring device may also act uniformly upon the bottom feed-rolls twodraw-springs may be used, one beyond each side of the booster orsecondary spring device.

Other features and advantages will hereinafter appear.

.In the accompanying drawings,

Figure l is a perspective showing the platenframe of a standardUnderwood noiseless typewriter, provided with the present improvements.

Figure 2 is a View showing the draw-spring, drawn out of the groove ofthe threaded anchorage-shaft preparatory to setting the end of thespring into one or another groove for adjustment of the spring tension.

Figure 3 is similar to Figure 2, but shows the draw-spring seated in oneof the grooves.

Figure 4 is a sectional side elevation, showing the noveldraw-spring-devices, and the feedrolls in normal positions.

Figure 5 is a plan of the platen-frame assemblage, partly broken away,showing the drawspring and booster-spring devices.

Figure 6 is a sectional view similar to Figure 4, but shows in additionthe booster-spring and how it is flexed to apply extra pressure to thefeedrolls.

Figure 7 is a sectional view similar to Figure 6, but shows thefeed-rolls cast ofi from the platen.

The usual Underwood platen I 0 is journaled by axle II in ends I2, I3,of a platen-frame. Front and rear feed-rolls I4 and I5 run upon thebottom of the platen. Type-bars I6 strike the platen ID. The feed-rollsare thrown on and off the platen by rocking a cam-shaft I1.

Novel spring-tension means for the feed-rolls I4 and I5 are applied andadjusted in the following manner.

Tension or draw springs I9 and 20 may be caught at their forward ends ingrooves 2| and 22 of a cross-rod 31, which, at its ends, is looselyconnected to front feed-roll-carrying rockerarms 23 and 24. Thesesprings tend to lift said arms, and press the front rolls up against theplaten.

Attached to the rearward end of each of springs I9 and 20 is a clip-hookor eye-piece 25, with an aperture 26 in its rear end. For adjusting thestretch and thereby the tension of the drawsprings I9, 20, there hasbeen provided a novel anchorage-shaft or cross-rod 21, which may berotatively supported in rocker-arms 28, 29, which carry the rearfeed-rolls I5. Said shaft 21 has screw-threaded portions to affordnotches 30, 3|, by means of which the eye-pieces 25 of the drawspringsmay be differently spaced, along said shaft 21, from the spring-endsthat are fixed by the grooves 2|, 22.

By using a hook 32, as seen in Figure 2, or pliers 33 as in Figure 1,the clips 25 of the springs are withdrawable from the notches 30 and 3|,for shifts to the right or left along the shaft 21, and may be seated inany desired notch 30 or 3|, to slant the springs more or less across thecrossrods 21, 31 and thereby regulate their tension.

Thus either draw-spring may be adjusted individually, so that adjustmentcan be effected in the pressure of the front and rear feed-rolls ateither the right or left of the roll-system. Since each spring I9, 20 isconnected to front and rear roll-carrying arms 23, 24 and 28, 29, itpresses the arms upwardly about their pivots, to press the end rolls upagainst the platen. The springs act together upon the middle rolls I4,I5. The tensioning of either spring by slanting it more in the describedmanner, will increase the pressure of the adjacent front and rear endrolls. Thus adjustment and correction may proceed until all rolls bearequally upon the platen. Or the pressure upon one end of the platen maybe made greater than upon the opposite end. Collective or omnibusadjustment may be effected by turning the shaft 21 by means of either ofthe easily accessible screw-slotted ends 34 or 35. As shaft 21 isturned, the eye-ends 25 of the springs are adjusted by the screw-threads30, 3| towards or away from the ends fixed in the grooves 2|, 22 ofcross-rod 31, thereby easing or increasing the tension. Thescrew-threads 30, 3| are shown as being of opposite hands, so that thetwo springs I9, 20 may slant rightward and leftward for the purpose ofneutralizing their end-thrust effects upon the cross-rods 21, 31.

Through this uniform collective feed-roll tensioning, there may alwaysbe a balanced or equalized feed-roll pressure. The universal adjustmentcan be effected, whether the original tensions of the springs 19 and 20are even or uneven.

It will be seen that the two lines of feed-rolls are connected, to movesimultaneously into and out of engagement, with the platen andworksheets This is effected by a feed-roll-release lever, not shown,having connection I8 with the usual cam-shaft I1, which extends alongthe platen, to control the release and restoration of the feed-roll armsand rolls.

It will be seen that a uniform and true tension can be secured on allthe rolls; and a properly proportioned feed-roll pressure may beeffected. There is provision of right and left individual springtension; and spring adjustment for normal feed-roll setting is securedby moving the eye-pieces 25 into selectable notches 33, 3| on rearanchorage-shaft 21. After the feed-rolls have been normally set to theplaten, with either even or uneven pressure, their pressure can becollectively increased or decreased by turning the dual threadedanchorage-shaft 21 in its bearings in the feed-roll-carrying arms 28, 29which may also coact with shaft-shoulders, indicated at 46, Figure 1, toretain said shaft 21 endwise.

Each of the rear feed-roll-carrying arms 28, 29 is pivoted upon a shaft41 and has a stabilizing hub 46. The carrying arms 23, 24 for the frontfeed-rolls I4 are also pivoted upon said shaft 41. Said pivoted shaft 41is supported in brackets 49 on the platen-frame base 40 and is retainedagainst endwise displacement by means of an end head 5| and an end nut52. The feed-roll-releasing cam-shaft I1 is also journaled in thebrackets 49 and is retained against endwise displacement by a collar 53and by abutment of the side of a cam-flat-forming notch 54 of said shaftI1 with arm 55 of the front feed-roll-carrying arm 24, the latter inturn abutting one of the brackets 49.

For applying extra pressure to the feed-rolls l4, I5, as forthick-card-feeding, a leaf spring 36 is used as a booster-spring and isclipped by means of a curled end 36 Figure 1, to the middle ofanchor-shaft 21. The front end of said spring abuts the under side ofthe front cross-rod 31 midway thereof. This spring 36 may be normallyunflexed, Figure 1, for regular feed-roll pressure, or, if extrapressure is desired, it may be flexed, Figure 6, by means of a finger orcam 38, attached to a rock-shaft 4|, journaled in a yieldable support 39adjacent the finger 38. Said boosterspring-controlling rock-shaft 4|extends beyond the platen-frame end I3 to present a handle 44, and issupported near its handle end by a hanger 42 secured to saidplaten-frame end by screw 43.

The yieldable support 39 constructed of spring metal and fastened to theplaten-frame base 40 by a screw 56 forms a resilient arm having its freeend curled as at 39 to form the bearing for booster-spring-controllingrock-shaft 4|. Said yieldable support 39 may have on either side of thesingle screw 56 a downwardly-projecting holding tongue 45 engaging thebase 40.

Upon casting off the feed-rolls I4, I5, as in Figure 7, the support 39will yield together with the finger 38 if the latter has been operatedto flex the booster-spring 36 for extra spring pres sure. The yieldingof the finger 38 through its support 39 thus obviates excessive flexingof the already flexed booster-spring 36 when the feedrolls are cast off.The rock-shaft 4| may be sufficiently loose in the bearing 39 and in thehanger 42 to permit it to swivel slightly in said hanger 42 inaccommodation to the yieldability of said support 39. The rear set ofbottom feedrolls has two middle feed-rolls I5, instead of a singlemiddle roll, in order to provide room, between said two middle rolls I5,for the boosterspring 36.

Variations may be resorted to within the scope of the invention, andportionsof the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typing machine, the combination of a platen-roll, two feed-rollsspaced circumferentially of the platen-roll, an individually pressiblesupporting device for each feed-roll for pressing the feed-roll againstthe platen-roll, a drawspring, and means for connecting said drawspringto both feed-roll-supporting devices and for regulating its force toregulate the feed-roll pressure, said means including a screw journaledin one of said feed-roll-supporting devices, one end of said springhaving a clip holdable by means of the thread of said screw, the otheend of said spring being attached to the other feed-roll-supportingdevice, said clip being withdrawalole from the screw-thread forplacement in different notches afforded by the latter to thereby quicklyvary the stretch and force of the spring, the stretch and force of thespring also being variable by turning said screw and thereby causingsaid clip to move therealong.

2. In a typing machine, the combination of a 'revoluble platen, twofeed-roll sets spaced circumferentially of the platen, an individuallypressible, supporting device for each feed-roll set for pressing thelatter against the platen, spring con nected across the twofeedrollsu;:-porting devices for pressing both of said feed-roll devicesjointly, by spring-flexing pressure applied transversely of said springat a point intermediate of connections to said feed-roll-supportingdevices, and means operable at will for applying and rerlioving saidspring-flexing pressure.

3. In a typing machine, the combination of a revoluble platen, twofeed-roll sets spaced circu1n-- ferentially of the platen, anindividually pressible, supporting device for each feed-roll set forpressing the latter against the platen, a spring connected across thetwo feed-roll-supporting devices for pressing both of said feed-rolldevices jointly, by spring-flexing pressure applied transversely of saidspring at a point intermediate of its connections to saidfeed-roll-supporting devices, and means operable at will for applyingand removing said spring-flexing pressure, said two feed-rollsupportingdevices being movable for withdrawing said feed-roll sets from theplaten, and said pressure-applying means being yieldable to obviateexcessive flexing of said spring when said feedrolls are withdrawn fromsaid platen while said means have been operated to apply said pressure.

4. In a typing machine having a revoluble platen, the combination of afeed-roll co-operative with the platen, pivoted arms spaced along theplaten for supporting the feed-roll and press" ing it against theplaten, an externally screwthreaded cross-rod connected to and extendingbetween said pivoted arms, a draw-spring for pressing said feed-rollagainst the platen and having one end seated in the cross-rod thread,said spring extending transversely from the crossrod to anchoring meansfor its other end, the stretch and force of said spring beingadjustable, for regulating the feed-roll pressure, by locating the firstdraw-spring end diiierently along said cross-rod by means of saidscrewthread.

5. The invention as set forth in claim 4, said first draw-spring endbeing withdrawable from the screw-thread for placement at differentpoints therealong, and said threaded cross-rod being rotatable, therebyto cause said screw-thread to adjust said first spring end therealong.

6. In a typing machine, the combination of a revoluble platen, twofeed-roll sets spaced circumferentially of the platen, twolaterally-spaced, pivoted supporting arms for each feed-roll set, a

cross-rod connecting each two arms and spaced from the pivot-axis ofsaid arms, one of said cross-rods being externally screw-threaded rightand left, respectively, at two sections of its length, and twodraw-springs connected across said cross-rods for pressing saidfeed-roll sets against said platen, the two draw-springs beingrespectively seated, at one end, in the right and left threadedsections, the other spring ends being anchored to the other cross-rod,said threaded cross-rod being rotatable, whereupon its right and leftthreads act to variably and oppositely slant said springs across saidcross-rods thereby to vary the stretch and tension of said springs foradjusting the feed-roll pressure, the opposite slanting of the springsacting to neutralize the end thrusts induced in the cross-rods by theslanted springs individually.

'7. In a typing machine, the combination of a revoluble platen, twofeed-roll sets spaced ciroumferentially of the platen, supporting meansfor each feed-roll set to press the latter against the platen, and twodraw-springs individually connected across the two supporting means forfeed-roll sets for pressing the latter against the platen, said springshaving connections whereby they may be adjusted independently toregulate their individual forces for regulating the distribution offeed-roll pressure along the platen, and whereby they may be adjustedjointly to regulate the whole distributed feed-roll pressure.

8. In a typing machine, the combination with the platen-roll, of twofeed-roll lines, front and rear, near the bottom of the platen,laterallyspaced rocker-arms for each line of feed-rolls,

a cross-rod connecting the rocker-arms that are associated with eachline of feed-rolls, each crossrod being spaced from its rocker-arm axis,and a draw-spring connected across the cross-rods and acting to pressboth lines of feed-rolls against the pie-ten, one of therocker-arm-connecting cross-rods having spring-end-receiving stationsdistributed longitudinally thereof, one end of the draw-spring beingdifferentially locatable by means of said stations, to slant the springdifferentially across said cross-rods for adjusting the spring-pressure.

9. In a typing machine, the combination with a platen-roll, of twonormally-spring-pressed feedroll lines spaced circumferentially of theplaten, a leaf-spring connected across said two feed-roll lines to servefor pressing both feed-roll lines against the platen, and means settableat will to press against said leaf-spring at a place between saidfeed-roll lines for optionally augmenting the normal-spring-pressure ofboth feed-roll lines, said set means being restorable at will forrestoring the normal feed-roll pressure.

10. In a typing machine having a platen, the combination of a feed-roll,an externally-threaded rod journaled to extend lengthwise of thefeed-roll axis, and a draw-spring having one end anchored and having theother end connected to engage the threads of said rod, said draw-springacting to press said feed-roll against the platen, the feed-rollpressure being adjustable by changing the stretch of said draw-spring bydifierentially locating said other end of the spring along said rod bymeans of said thread, either by turning said rod for micrometricadjustment of said stretch, or by drawing said other spring-end out ofone place of engagement with said threads and shifting it to anotherplace.

11. In a typing machine, the combination of a platen-roll, twofeed-rolls spaced circumferentially of the platen-roll, primaryspring-means acting to press said feed-rolls against the platenroll withordinary pressure, a secondary springdevice having means, normally inidle condition for both feed-rolls, for pressing both of said feedrollssimultaneously to apply additional springpressure jointly to both ofsaid feed-rolls, and a controller common to said feed-rolls anddifferentially settable at will to put said additionalpressure-applyingmeans in effective condition for both feed-rolls, or, conversely, torestore said additional-pressure-applying means to said normal idlecondition.

12. In a typing machine, the combination with the platen-roll, of twofeed-roll lines, front and rear, near the bottom of the platen,laterallyspaced rocker-arms, fulcrumed at a suitable axis, for each lineof feed-rolls, two cross-rods, one cross-rod connecting the rocker-armsthat are associated with one line of feed-rolls, and the other cross-rodconnecting the rocker-arms that are associated with the other line offeed-rolls, each cross-rod being spaced from the companion rocker-armaxis, and a draw-spring connected across the cross-rods and acting topress both lines of feed-rolls against the platen, one of therocker-arm-connecting cross-rods having an external screw-thread thatforms spring-end-receiving stations distributed longitudinally thereof,one end of the draw-spring being retractable from said screw-thread forquick lateral shift of said end from one station to another, to slantthe spring differentially across said cross-rods for adjusting thespring-pressure, said screw-threaded rod being rotatable formicrometrically adjusting the tension of said draw-spring supplementallyto the tension-adjustment obtained by retracting said spring-end fromone station and replacing it at another station.

13. In a typewriting machine, the combination with a platen-roll, of afeed-roll, a structure for supporting and pressing said feed-rollagainst the platen, and a draw-spring having connections enabling it topull upon said structure and in transverse direction of the feed-rollaxis, said connections including a rod having a screw-thread along andby means of which one end of said spring is shiftable laterally to varythe transverse direction in which said spring pulls, and thereby varyits pull to regulate the feed-roll pressure effected by saiddraw-spring.

14. In a typewriting machine or the like, in combination, a structureadapted to be springforced, an externally-threaded screw-rod, and aspring-device cooperating therewith to springforce said structure, saidspring-device including an element having two ends, one end beingdifferentially loca-table, relatively to the other, on and along saidrod by means of said screwthread so as to slant said elementdifferentially to said rod and thereby vary the stretch and resultantforce of said spring-device, said firstmentioned element-end beingadapted to be disengageable from said screw-thread at will for a quickshift to one or another station along said thread, said screw-rod beingrotatable to screwshift said first-mentioned element-end along saidthread for regulating micrometrically said stretch and force.

WILLIAM F. HELMOND.

